Taipei, Sept. 5 (CNA) At least 235 domestic food companies and restaurants have used the brand of questionable lard-based oil made with recycled kitchen waste, the Food and Drug Administration (FDA) said Friday. An investigation found that Kaohsiung-based Chang Guann Co. has supplied 51,981 18-liter cans of its "Chuan Tung" cooking oil to companies across Taiwan, according to FDA chief Yeh Ming-kung. Those affected include well-known companies such as Triko Foods Co., Ve Wong Corp., Taiwan Sugar Corp., Mei & Mei restaurant chain, WHM Co., Yu Jen Jai pastry shop, Chi Mei Frozen Food Co., Hawdii and Kong Yen Foods Co. Wei Chuan Foods Corp., another customer of Chang Guann and a major player in the industry, has already recalled 12 products including its popular canned pork fiber and meat paste immediately following the exposure of the bad oil Thursday. According to Chang Guann, the oil was sourced between February and August by an individual named Kuo Lieh-cheng, who allegedly worked with five others to use a phony waste processing company as a front to collect oils meant to be recycled for uses other than human consumption. Chang Guann allegedly bought 242 metric tons of oils provided by Kuo and turned them into 782 metric tons of products sold as lard-based oils. Kuo, now facing prosecution, is believed to have gone so far as to collect grease by-products from leather processing plants to market as edible oils. (By Lung Pei-ning and Y.F. Low)